History of the Thailand Flag: Ayutthaya Red Flag to the 1917 Trairong
Thailand’s modern red-white-blue flag grew out of earlier royal and maritime flags used over several centuries.
Ayutthaya-era red flags
Thailand’s government traces the earliest Thai flag tradition to the Ayutthaya period, when plain red flags were flown on ships to identify them as belonging to Siam.
Rama I and the royal chakra flag
During the reign of King Rama I, royal ships were distinguished from civilian vessels by adding a white Sudarshana Chakra to the red field.
Why flags changed over time
As Siam’s state institutions and international relations developed, increasingly standardized designs were needed to distinguish the kingdom’s ships and official representation.
1917: the Trairong is established
King Vajiravudh (Rama VI) introduced the modern five-stripe tricolour through the Flag Act B.E. 2460, corresponding to 1917. The flag became known as the Thong Trai Rong, or tricolour flag.
Why red, white and blue?
The final color scheme created a symmetrical five-band design. Official meanings associate red with the nation, white with religion and blue with the King.
1936 amendment
Thailand’s government notes that the Flag Act was amended in 1936 while the modern Trairong design remained in use.
What has stayed unchanged?
The stripe order—red, white, blue, white, red—and the wider central blue band remain the defining features of Thailand’s flag today.
Timeline
| Ayutthaya period | Plain red ship flags |
|---|---|
| Rama I era | Royal red flag with white chakra |
| 1917 | Modern Trairong established |
| 1936 | Flag Act amended |
